Debating the Legality of the Post-9/11 ‘Forever War’

A helicopter picks up U.S. soldiers after a night raid in Afghanistan’s Paktika Province.
Matt Robinson/Reuters

The Authorization for the Use of Military Force, passed by Congress in the immediate aftermath of the September 11, 2001, attacks, has been cited by the Bush and Obama administrations as sanctioning far-ranging military operations. Four scholars offer their perspectives on the AUMF’s legacy fifteen years on.

A helicopter picks up U.S. soldiers after a night raid in Afghanistan’s Paktika Province.
Matt Robinson/Reuters

Expert Roundup

CFR fellows and outside experts weigh in to provide a variety of perspectives on a foreign policy topic in the news.

In the week after September 11, 2001, Congress authorized the president “to use all necessary and appropriate force against those nations, organizations, or persons he determines planned, authorized, committed, or aided the terrorist attacks,” as well as against those who “harbored such organizations or persons.” Fifteen years later, that resolution, known as the Authorization for the Use of Military Force, or AUMF, underpins wide-ranging U.S. military operations targeting a diffuse jihadi movement.

Though just sixty words long, Presidents George W. Bush and Barack Obama have cited the AUMF as the domestic legal grounds for the war in Afghanistan, indefinite detentions, and targeted killings beyond conventional battlefields. The Obama administration has advocated a broad definition of what constitutes an “associated force” of al-Qaeda or the Taliban to carry out air strikes or deploy special forces in Iraq, Pakistan, Somalia, Syria, and Yemen, even as critics say that many of the militants who have been targeted bear at most a tangential connection to the perpetrators of the 9/11 attacks. Still, many lawmakers and jurists have seconded the administration’s view, offering the White House broad discretion.

Even as a wide array of critics and, indeed, the Obama administration have called the AUMF outdated, congressional efforts to repeal or replace it have faltered amid disagreement over what should succeed it. National security hawks seek to provide the president with broad latitude to target groups such as the self-proclaimed Islamic State, while civil libertarians hope to impose limits on military action by specifying objectives, geographic limits, or sunset provisions.

Here, four scholars offer their perspectives on the AUMF’s legacy and its applicability to today’s armed conflicts.

Michael J. Glennon, Professor of International Law, Fletcher School of Law and Diplomacy, Tufts University

The Obama administration’s strained interpretation of the 2001 AUMF wholly defeats the purposes of the Constitution’s framers.

The administration’s interpretation of the AUMF defeats the founders’ purposes.

The founders empowered the executive to use defensive force when threats to the nation are so imminent that Congress has no time to act. But in non-emergencies, they required congressional approval prior to the use of force. This framework, the founders believed, advanced the purposes of collective deliberation, transparency, political consensus, and democratic accountability while safeguarding the nation.

The consequences of this untenable interpretation are unsurprising. There has been no meaningful debate on whether the U.S. national interest requires a war against the Islamic State. The administration’s nod toward transparency, such as it is, has consisted of vague speeches, anonymous asides to friendly journalists, and unsigned, cursory legal opinions given privately to hand-picked members of Congress. No member is politically accountable because no member has been required to vote on an AUMF specific to the Islamic State. “It’s not hard to imagine that a future president will use this example to also justify initiating war without the permission of Congress,” Senator Tim Kaine said in May.

Captain Nathan Smith, an Army intelligence officer ordered to participate in the war against the Islamic State, has challenged his orders in court, saying they violate the 1973 War Powers Resolution. The resolution, vindicating the founders’ purposes, requires the president to remove armed forces from hostilities within ninety days of deploying them unless Congress specifically approves the use of force. On August 19, I filed an amicus brief, with the Constitution Project, a bipartisan research institute, supporting Smith’s action. We argue that the administration’s reading of the 2001 AUMF as a general authorization is disallowed by the resolution’s requirement that any use of force be specifically authorized.

Whether Smith prevails will provide insight into whether the founders’ framework still governs.

As legal adviser to the National Security Council, I was in the Situation Room at the time of the 9/11 attacks and helped draft the 2001 AUMF, which has provided the domestic legal basis for the use of force against al-Qaeda and associated terrorist groups for the last fifteen years. I have long argued—including in a 2010 op-ed, “A Counterterrorism Law in Need of Updating”—that the 2001 AUMF should be updated to provide explicit authority to use force against terrorist groups that threaten the United States but were not involved in the 9/11 attacks. The rise of the Islamic State has made it clearer still that Congress should enact new legislation, both to update the 2001 AUMF and, specifically, to authorize the use of force against the Islamic State.

The next Congress should repeal and replace the outdated AUMF.

Because Congress has failed to pass a new authorization, the Obama administration has relied for the last two years on the 2001 AUMF as the legal basis for the use of force against both al-Qaeda and the Islamic State. It has claimed that authority based on the strained legal interpretation that the Islamic State is a descendant of al-Qaeda, even if the two groups are not actually associated. This interpretation has permitted both the executive branch and Congress to duck the requirement in the War Powers Resolution that the president may not commit U.S. armed forces for more than sixty days unless authorized by Congress. But it is undemocratic for the 114th Congress not to have provided new and specific authority, and the executive branch’s reliance on the 2001 AUMF is now being challenged in federal court.

Several members of Congress, most notably Democratic vice presidential nominee Senator Tim Kaine, have offered draft legislation that would specifically authorize the use of force against the Islamic State. (Hillary Clinton has said that the 2001 AUMF authorizes use of force against the Islamic State, but that she “would like to see it updated.”) In February 2015, the White House offered its own proposal, which would have provided broad authority to use force against the Islamic State in multiple countries, but expire after three years. It would not have permitted “enduring offensive ground combat operations.”

Almost all members of Congress support the use of military force against the Islamic State, but Republicans and Democrats have been unable to agree on specific language. Progressive Democrats have been reluctant to vote for any new war powers that are not strictly limited by geography and duration. They have viewed the White House proposal as much too broad. Most Republicans, on the other hand, have not wanted to restrict the president’s authority. While they may agree that reliance on the 2001 AUMF is strained, they do not want limits by country, type of force, or duration.

The 2001 AUMF was hastily drafted after 9/11 to authorize the use of force against the perpetrators of those attacks. The next Congress should repeal the outdated AUMF and replace it with one that authorizes the new president to use necessary and appropriate force not only against al-Qaeda and associated groups, but also against the Islamic State and other newer terrorist groups that threaten the United States and its interests.

Elizabeth N. Saunders, Stanton Nuclear Security Fellow, Council on Foreign Relations, and Assistant Professor of Political Science and International Affairs, George Washington University

In the fifteen years since the 9/11 attacks, Congress has often called on the president to comply with the War Powers Resolution (WPR), but has rarely used it to restrain him. Yet Congress has not authorized recent interventions either. During the 2011 Libya intervention, for example, members of Congress criticized President Obama for failing to seek authorization, but the operation proceeded without congressional authorization beyond the sixty-day limit required by the resolution. So why has Congress’s bluster not been matched by legislative action?

Taking a public stand on the use of force can be politically risky for members of Congress.

Many explanations are institutional. As CFR’s James M. Lindsay noted in hisseriesofblogposts on the constitutionality of the Libya operation, one reason Congress so rarely imposes its will on the president is that the president can act first, forcing Congress to put in the effort to stop him. The president’s veto power also means that the executive only needs thirty-four Senate votes to proceed. As Lindsay put it, “Facing those daunting odds, most members of Congress don’t see the point in challenging the White House. Why waste valuable legislative energy tilting at windmills?”

The New York Times’sCharlie Savage, reporting on President Obama’s decision to treat the war against the Islamic State as an extension of the post-9/11 war on terrorism rather than seek a new AUMF, noted another reason for the lack of formal authorization: Obama believed that Congress was “too dysfunctional to vote on any war authorization within sixty days.”

But there is also a political reason why the war powers issue remains unresolved: Congress may like it that way (and so might the president, for that matter). Taking a public stand on the use of force can be risky for members of Congress; debating the WPR channels congressional criticism toward procedural issues instead. This kind of process-oriented debate allows lawmakers who may feel they need to lob criticism at the president to do so while avoiding potentially futile or controversial debates, much less votes, on substantive issues that might leave them appearing weak on national security, or having supported a war that has turned unpopular. Additionally, by confining debate to procedural issues, members of Congress can paper over their own disagreements about the president’s chosen course, such as on the size of the mission or whether the decision to use force in the first place was wise.

The cycle of debate and inaction on war powers is not simply the product of congressional inertia, dysfunction, or shirking. Rather, it serves a useful political function for both the executive and legislative branches. Legal scholars may be right that the country would be better served by a real debate when the president takes the country into hostilities, but as long as members of Congress and the president are content with the status quo, a new AUMF will not take shape.

Samuel Moyn, Jeremiah Smith, Jr. Professor of Law and Professor of History, Harvard University

We know from history that Congress has a momentous initial task in signing off on war. After all, it is far from unprecedented for America’s military interventions to expand afterwards.

The AUMF opened an era of indefinite war.

In his classic autopsy of Vietnam, for example, the great liberal law professor John Hart Ely showed how the Gulf of Tonkin Resolution or subsequent appropriations bills might well have covered nearly everything that followed over the following decade—even after Congress retroactively pretended to limit the scope of its initial permission slip.

Ely concluded that something had gone dreadfully wrong when the Cold War dawned because the original constitutional understanding—that authority to deploy force would be shared between the executive and the legislative branches—was given up. Nor did the end of the Cold War allow a return to the status quo ante.

Even more than the Gulf of Tonkin Resolution, the AUMF of September 18, 2001, opened an era of indefinite war. It has proven more elastic than prior congressional grants of war power both because the enemy is much more fungible and because the conflict has no clear geographical boundaries. But most important, where atrocity in Vietnam eventually helped make that war politically unpopular, helping bring about its end, President Barack Obama has understood that if war is made clean and “humane,” it can be made endless. Drone strikes, among other practices, have brought some opprobrium on the forever war, but nowhere near enough to compel its de-escalation, perhaps because drones epitomize a conflict freer of collateral damage than any counterinsurgency in history.

As law professors Curtis Bradley and Jack Goldsmith have recently shown, Obama’s reinterpretation of the AUMF as apparently limitless is one of his main legacies—and the administration has construed international law so that it matches the president’s AUMF authority, rather than limits it. I would simply add that civil libertarians’ and human rights activists’ vigorous pursuit of constraints on how presidents fight their wars—however honorable—has, paradoxically, made it tougher to challenge the expansion of presidential authority to go to war in the first place. We have coupled weakened laws on whether war can continue with strengthened laws on how they are fought. It is the perfect recipe for the endless, if low-level, use of force.

The AUMF is a big part of a depressing tale for our times for anyone who believes that all power, and especially the power to go to war, must have limits. We might have learned this lesson after Vietnam, but it turns out that we only responded by making war less atrocious.